Structure and Magnetic Properties of ${\hbox {Ba}}_{1\hbox {-}{\rm x}}{\hbox {La}}_{\rm x}{\hbox {Fe}}_{12}{\hbox {O}}_{19}$ Prepared by

M-type Barium hexaferrite (BaFe₁₂O₁₉) with substitution of Ba²⁺ by rare earth metal La³⁺ were prepared by solid state synthesis method from as-prepared powder of barium monoferrite (Ba_1-xLa_xFe₂O₄) (x=0.0, 0.1 and 0.2). The structural and magnetic properties of Ba_1-xLa_xFe₁₂O₁₉ were investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. The refined XRD patterns suggests the formation of single phase hexaferrite. With increased La substitution (x), the saturation magnetization increased and reached maximum at x=0.1 and decreased at x=0.2, without any noticeable change in coercivity. Fitted Mössbauer spectra of Ba_1-xLa_xFe₁₂O₁₉ showed increase in hyperfine field and a transition from Fe³⁺ ion to Fe²⁺ ion at 2b site. The present work demonstrates a new methodology for two stage substitution.